Improvement in grinding-m ills



YOUNG & McLEAN.

Grinding Mill.

No. 56,659. Patented July 24, 1866.

WIT/(E5555 15 '9, Q @"f W UNITED STATES PATENT GrFIct-t.

OHARLES D. YOUNGS AND JAMES MOLEAN, OF VVATERLOO, NEW'YORK.

IMPROVEMENT IN GRINDING-MILLS.

Specification forming part of Letters Patent No. 56,659, dated July 24, 1866.

To all whom it may concern:

Be it known that we, CHAS. D. YOUNGS and JAMES MGLEAN, of Waterloo, in the county of Seneca and State of New York, have in vented certain new and useful Improvements in Grinding-Mills; and we do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, making part of this specification.

Figure 1 is a central vertical section of a grinding-mill and fan-case provided with our improvements; Fig. 2, a plan of the bed-stone and a horizontal section of the fan-case.

Like letters of reference in dicate correspondin g parts in both figures.

It has long been a favorite idea to introduce cold air between millstones for the purpose of preventing the heating of the meal. Several devices have been proposed to secure this result. In one oblique passages are made through the running-stone, with caps or hoods outside to collect the air and force it down by the motion of the stone. In others exhaust-pipes are connected with the casing of the stones in such a manner as to draw the air down through the eye of the stones, and thence outward.

Our invention consists in an arrangement of blast-tubes opening into enlargements of the furrows between the stones, and pointing outward in different directions, to distribute the blast equally, and used in connection with a draft-tube extending from the top of the case, by which moisture may be drawn off, said tubes being connected with an exhaustfan to produce the necessary action.

As represented in the drawings, A B are respectively the ordinary running and bed stones of a grinding-mill, mounted on a suitable frame, 0, and D the casing that surrounds them.

The bed-stone B is provided with the ordinary furrows a at. Opening into the extremities of these from the center of the stone are the ends I) I) of any desirable number of blastpipes E E, extending downward through the stone, and then into a fan-case, G, with which they connect.

The ends I) b are bent outward so as to rest below the level of the surface of the stone, and are made so short as not to interfere at all with the regularity of the grinding-surface, the extremity of the furrows being simply enlarged to admit them. The ends of the pipes point in opposite directions, so as to distribute and equalize the blasts between the stones.

With the top of the casing D connects an exhaust-pipe, H, which simply extends to the fan-case G and opens through its top, as shown in Fig. 1.

The fan-case is of any ordinary construction, having an induction, 0, for admitting cold air, and an eduction, d, for forcing it into the blast-pipes. It is provided with an ordinary fan, K.

The advantage of this arrangement consists, essentially, in the combination of a positive blast, which is distributed properly between the stones, with an exhaust-draft, that draws off the heated air and the moisture that would otherwise collect and injure the flour, the whole forming a circuit from the fan-case to the stones. So far as we are aware this effect is new.

In all devices with which we are acquainted either the blast or the draft is used alone, and not in combination with the other.

Where air is simply introduced between the stones by the oblique passages, as at first alluded to, the blast is wholly insufiicient to keep the stones cool, and there is no means of drawing off the moisture and heat that are evolved; and where a draft is simply produced through theeye of the stones, and thence into the exhaust-pipe, the eflect is scarcely improved, if even it is equal to the first, since the current between the stones must be very slight, owing to the admission of air at the discharge-spout of the casin g, and to the fact that the air that enters the eye simply passes through one side toward the escape-pipe.

It will be seen that by the arrangement of our blast-pipes opening in difierent ways the air is distributed equally in all directions, and that the intensity of the blast is measured only by the capacity of the fan. In this manner'the stones may be kept cool, and such moisture as is formed is drawn off into the combination with an exhausttube, H, coufan-ohamber and condensed by coming in conneeted with the same fan-case G, for the eX- taot with the cold induction air. traction of moisture, as herein set forth.

What we claim as our invention, and desire to secure by Letters Patent, is

The blast tubes E E, having their ends I) b opening outward in opposite directions in the Witnesses: extremities of the furrows of the bed-stone to Tues. PARKS, distribute the blast properly, employed in 1 O. BRANORTHWIOK. 

